Baumhauerite is a rare lead arsenic sulfosalt often found as distinct, metallic, tabular crystals within dolomitic marble. It is most famous from the Binn Valley locality in Switzerland, where it occurs in association with various other complex sulfosalt minerals.
Is this baumhauerite?
5-step field checkRun through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.
- 1Test the hardnessTry to scratch baumhauerite with a known reference. Baumhauerite sits at Mohs 3, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: chocolate-brown.
- 3Read the lusterHold the specimen under a strong light. Luster: metallic.
- 4Match the color rangeCompare against the expected color range: lead gray, steel gray.
- 5Look at form & habitCrystal system: triclinic. Typical habit: crystalline.
Often confused with
Baumhauerite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside baumhauerite
Minerals reported to co-occur with baumhauerite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Pb₃As₄S₉
- Mohs hardness
- 3
- Density
- 5.33-5.44 g/cm³
- Colors
- Streak
- Chocolate-brown
- Luster
- Metallic
- Transparency
- Opaque
- Crystal system
- Triclinic
- Crystal habit
- Crystalline
- Cleavage
- Perfect on {100}
- Rarity
- Rare
- Uses
- Collector, Scientific research
- Host rock
- In sugary dolostone (Binntal, Switzerland)
Where rockhounds find baumhauerite
Classic worldwide localities
- Sterling Hill, Ogdensburg, Sussex Co., New Jersey, and at the Zuni mine, Silverton, Colorado, USA
- Lengenbach quarry, Binntal, Valais, Switzerland (type locality)
- Mooseck, near Golling, Salzburg, Austria
- Seravezza marble quarries, 20 km southwest of Carrara, Tuscany, Italy
- Madoc, and in the Hemlo gold deposit, Thunder Bay district, Ontario, Canada
- Novoye, Kaidarkan, Kyrgyzstan
Field-hunting tip
Where it forms: In sugary dolostone (Binntal, Switzerland). If you start seeing realgar, pyrite, dolomite in float, you are in the right ground. Typical habit: crystalline. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify baumhauerite?+
Where is baumhauerite found?+
Is baumhauerite safe to handle?+
What rocks look like baumhauerite?+
What minerals are found with baumhauerite?+
What kind of rock does baumhauerite form in?+
What is baumhauerite used for?+
Find baumhauerite on the map
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